1. Field of the Invention
The present invention relates to coke production facilities, and more specifically to coke dry quenching chambers. Most efficiently the invention can be used in the coke chemical-recovery industry.
Although the method of coke dry quenching has been known since the beginning of the last century, the attempts to improve apparatuses for carrying out this method have not been ceased until present. These attempts were aimed mainly at upgrading the quality of coke and raising the efficiency of the quenching process. A relatively great number of patents granted for improvements in such apparatus in recent years in a number of countries indicates that this problem remains an urgent one.
2. Prior Art
There is known an apparatus for dry coke quenching (cf. U.S. Pat. No. 3,959,084), incorporated in a two-chamber quenching installation. This apparatus comprises a vertical chamber having a charging hole in its roof and a discharging gate in the bottom. In the lower portion of the chamber is disposed a means for feeding quenching gas. A branch pipe to let a hot gas out is fixed to one of the walls of the chamber in the upper portion thereof.
Adjacent to the discharging gate is a chamber for cooling the coke with water. The presence of this cooling chamber is caused by the necessity to equalize temperature through the whole mass of the coke being treated, which is not achieved by using only dry quenching. This is due to the fact that the amount of quenching gas passing through the coke disposed close to the outlet branch pipe is greater than that of the gas passing through the coke in zones remote therefrom.
Though the resulting coke produced at this quenching installation possesses anisotropic properties, operating the said quenching installation is associated with a number of disadvantages inherent in all the known methods of wet quenching.
It is a matter of common knowledge that the thermal stresses occurring in the coke in the case of using wet quenching causes cracks in the coke lumps and hence fragmentation thereof, which fragmentation is favoured by the water getting inside these cracks and rapidly evaporating therein. As a result, the coke thus produced contains a great number of small fractions which cannot but affect the operation of a blast furnace.
Another undesirable phenomenon occurring in the case of the wet quenching process is the formation of hydrogen sulfide and sulfurous anhydride, which escape together with water vapor into the atmosphere.
The above disadvantage has been overcome in a coke one-stage dry quenching apparatus (cf. British Pat. No. 1,433,575) which comprises a vertical chamber having in its roof a charging hole, in its bottom a discharging gate, and within its walls gas exhaust conduits, and a annular collector having a common outlet pipe. The gas exhaust conduits communicate the inner space of the chamber with the annular collector. In the lower portion of the chamber is disposed a means for feeding a quenching gas.
This coke quenching apparatus is free from disadvantages associated with wet quenching applied at the second stage of quenching in the aforesaid apparatus. In addition, removal of quenching gas from the quenching chamber through a plurality of peripheral gas exhaust conduits makes it possible to equalize to some extent the coke cooling conditions.
It has been established, however, that the amount of the quenching gas passing through the peripheral gas conduits disposed close to the common gas withdrawal conduit than through the peripheral gas conduits remote therefrom, which is due to the fact that the pressure in the collector is minimal in the zone close to the common gas withdrawal conduit and increases with the increase of a distance therefrom, which is responsible for that a portion of the coke being treated is not sufficiently cooled. To remedy this, more quenching gas is blown, thereby affecting the efficiency of the process.
It is clear, that this disadvantage could be removed by means of a proportioned removal of gas from each individual peripheral conduit through an individual vacuum pump. This, however, is not advisable, since a relatively great number of the peripheral gas conduits (15-30) would involve a more complex construction.